Washing machine

ABSTRACT

Provided is a washing machine. The washing machine includes: a washing drum accommodated in an outer drum 3; a motor for rotating the washing drum; a water tank for receiving detergent water containing detergents from the outer drum; a circulating path for taking the detergent water and injecting the detergent water from an upper side into the washing drum; a pump for taking the detergent water in the water tank into the circulating path and lifting the detergent water in the circulating path; and a control part for executing a washing operation including a dewatering washing process. In the dewatering washing process, circulating treatment, impregnation treatment and dewatering treatment are repeatedly conducted.

TECHNICAL FIELD

The present disclosure relates to a washing machine.

BACKGROUND

In a drum washing machine described in a following patent literature 1, a beating washing process and a subsequent squeezing washing process are conducted in a washing operation. In the beating washing process, forward rotation, reverse rotation and pause of a roller-shaped rotating drum arranged in a bucket are repeatedly conducted, so as to repeatedly conduct actions of lifting and dropping washings in the roller-shaped rotating drum. In the squeezing washing process, a roller-shaped washing drum is rotated at a speed higher than that in the beating washing process, so that the washings are thrown and pressed onto an inner surface of the roller-shaped washing drum under the centrifugal force, and detergents in the washings are squeezed out of the roller-shaped washing drum through small holes in a circumferential surface of the roller-shaped washing drum. The drum washing machine is provided with a water tank. Part of washing water is transferred to the water tank at the end of the beating washing process, thereby alleviating weight of the bucket. Therefore, reduction of vibration and noise in the squeezing washing process can be achieved.

Under a condition where the washings are washed through the rotation of the washing drum for accommodating the washings and detergent water containing the detergents, a washing effect is always expected to be improved. Especially, unlike the drum washing machine in the patent literature 1, for a vertical washing machine which includes a washing drum having an axis that extends longitudinally, since the detergent water is accumulated towards a bottom side in the washing drum, a problem that only lower parts of the washings in the washing drum are impregnated with the detergent water exists. Therefore, it is difficult to improve the washing effect of the detergent water.

TECHNICAL LITERATURE OF PRIOR ART Patent Literature

Patent Literature 1: Japanese Laid-open patent publication No. 8-299658

SUMMARY Problems to be solved by the Disclosure

In view of the background described above, the present disclosure aims to provide a washing machine which can improve the washing effect when washings in a washing drum are washed through detergent water and rotation of the washing drum having an axis that extends longitudinally.

Solution for Solving the Problem

The washing machine of one or more embodiments of the present disclosure includes: an outer drum which can store water; a washing drum accommodated in the outer drum and used for accommodating washings, where the washing drum has an axis extending longitudinally and multiple through holes for enabling water to flow between the washing drum and the outer drum; a motor for rotating the washing drum; a water tank connected to the outer drum and used for receiving detergent water containing detergents from the outer drum; a circulating path for taking the detergent water from the water tank and injecting the detergent water into the washing drum from an upper side of the washing drum; a pump for taking the detergent water in the water tank into the circulating path and lifting the detergent water in the circulating path; and an execution unit for executing a washing operation where the washing operation includes a dewatering washing process which repeatedly conducts circulating treatment, impregnation treatment and dewatering treatment, the circulating treatment is to drive the pump to enable the detergent water in the water tank to circulate between the washing drum and the circulating path and to sprinkle the detergent water on the washings in the washing drum; the impregnation treatment is to stop driving the pump after the circulating treatment and to enable the detergent water to impregnate the washings in the washing drum and return to the water tank; the dewatering treatment is to drive the motor to rotate the washing drum to dewater the washings after the impregnation treatment.

In some embodiments, the execution unit drives the motor in at least one circulating treatment to rotate the washing drum.

In some embodiments, the water tank is provided with an exhaust hole; and the washing machine includes an exhaust pipe which has one end part connected to the exhaust hole and another end part connected to an upper part of the outer drum.

In some embodiments, the washing machine includes: a water supply path for supplying water for the washing drum; and a detergent accommodating part connected to the water supply path and used for accommodating the detergents; the water supply path has a discharge opening used for discharging the water that passes through the detergent accommodating part and flows through the water supply path towards a position staggered with the washings in the washing drum.

In some embodiments, the circulating path includes a main flow path and a branch flow path, the main flow path has a discharge opening facing the washing drum from an upper side, the branch flow path branches from the main flow path and is connected to one of the outer drum and the water tank; and the washing machine includes a reversing valve used for switching a flow of the detergent water in the circulating path to one of the main flow path and the branch flow path.

In some embodiments, the washing machine includes a flow path connecting the outer drum to the water tank; and a valve for opening and closing the flow path; and the execution unit closes the valve in at least one impregnation treatment to accumulate the detergent water in the washing drum.

Effects of the Disclosure

According to some embodiments of the present disclosure, the washing machine accommodates the washings in the washing drum which has the axis that extends longitudinally. The water that flows between the outer drum and the washing drum through the through hole of the washing drum is accumulated in both of the outer drum and the washing drum. The water tank connected to the outer drum can receive the detergent water containing the detergents from the outer drum. After the pump takes the detergent water in the water tank into the circulating path and lifts the detergent water in the circulating path, the detergent water is injected into the washing drum from the upper side of the washing drum.

The execution unit executes a washing operation including a dewatering washing process which repeatedly conducts circulating treatment, impregnation treatment after the circulating treatment and dewatering treatment after the impregnation treatment. In the circulating treatment, the execution unit drives the pump to enable the detergent water in the water tank to circulate between the washing drum and the circulating path and sprinkle the detergent water on the washings in the washing drum. In the impregnation treatment, the execution unit stops driving the pump and enables the detergent water to impregnate the washings in the washing drum and return to the water tank. In the dewatering treatment, the execution unit drives the motor to rotate the washing drum to dewater the washings.

After the circulating treatment is performed for several times, the detergent water in the water tank is sufficiently sprinkled on the washings in the washing drum. In the impregnation treatment after each circulating treatment, the washings are treated into a state equivalent to soaking through an adequate amount of detergent water. Thus, the dirt floats out of the washings efficiently. Moreover, in the dewatering treatment after each impregnation treatment, the dirt is squeezed out of the washings along with the detergent water under the centrifugal force caused by the rotation of the washing drum. In the impregnation treatment before the dewatering treatment, the detergent water in the outer drum and the washing drum is returned into the water tank. Thus, in the dewatering treatment, since the washing drum can successfully rotate to target maximum revolutions without being hindered by the detergent water, the high-speed rotation of the washing drum enables to efficiently dewater the washings and to remove the dirt from the washings.

As a result, the washing effect in the dewatering washing process which is conducted through the detergent water and the rotation of the washing drum having the axis that extends longitudinally is improved.

In some embodiments, the execution unit drives the motor in at least one circulating treatment so that the washing drum is rotated. Thus, the detergent water injected into the washing drum from the circulating path can be evenly sprinkled on the washings in the washing drum throughout the entire region in the rotating direction of the washing drum. Therefore, the dewatering washing process can further improve the washing effect.

In some embodiments, when the washing water is returned into the water tank in the impregnation treatment, since air in the water tank escapes out of the water tank through the exhaust hole, the detergent water can successfully flow into the water tank. The exhaust pipe has one end part connected to the exhaust hole and another end part connected to the upper part of the outer drum. Thus, since air bubbles in the water tank are guided into the outer drum even if the air bubbles enter the exhaust pipe, the case where the air bubbles block the exhaust pipe can be inhibited. In addition, since another end part of the exhaust pipe is connected to the upper part of the outer drum, the another end part is located in a position higher than an upper limit water level in the outer drum. Therefore, the water in the outer drum can be prevented from overflowing into the exhaust pipe.

In some embodiments, the discharge opening of the water supply path discharges the water that passes through the detergent accommodating part and has the detergents towards a position staggered with the washings in the washing drum. Thus, a case can be inhibited where the washings cannot be evenly washed because ultrahigh-concentration detergents before dissolved in the water are only attached to part of the surface of the washings.

In some embodiments, the flow of detergent water in the circulating path is switched to the main flow path, so that the detergent water is circulated between the washing drum and the circulating path. The flow of detergent water in the circulating path is switched to the branch flow path, so that the detergent water in the circulating path directly enters the outer drum or the water tank through the branch flow path instead of arriving at the washing drum. Thus, since the frequency of the detergent water flowing through the pump can be increased and the stirring of the detergent water by the pump can be promoted, the detergents can be efficiently dissolved in the water to generate high-concentration detergent water. Therefore, in the dewatering washing process, the washing effect through the high-concentration detergent water can be further improved.

In some embodiments, in at least one impregnation treatment, the execution unit closes the valve which is used for opening and closing the flow path communicating the outer drum and the water tank, so that the detergent water is accumulated in the washing drum. Thus, since the washings can be efficiently treated into a state equivalent to soaking through an adequate amount of detergent water accumulated in the washing drum, the washing effect can be further improved in the dewatering washing process.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating a washing machine in an embodiment of the present disclosure;

FIG. 2 is a block diagram illustrating an electrical structure of a washing machine;

FIG. 3 is a flow chart illustrating a control action in a dewatering washing process;

FIG. 4 is a schematic diagram illustrating a washing machine in a first variation example;

FIG. 5 is a schematic diagram illustrating a washing machine in a second variation example; and

FIG. 6 is a schematic diagram illustrating a washing machine in a third variation example.

LIST OF REFERENCE SIGNS

1: washing machine; 3: outer drum; 3F: upper part; 4: washing drum; 4E: through hole; 5: motor; 6: water supply path; 6B: discharge opening; 8: detergent accommodating part; 9C: upper flow path; 11: circulating path; 11B: discharge opening; 11D: main flow path; 11E: branch flow path; 12: pump; 13: water tank; 13A: exhaust hole; 22: second drain valve; 23: exhaust pipe;

23A: one end part; 23B: another end part; 30: control part; 35: reversing valve; J: axis; Q: washings; and Z1: upper side.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram illustrating a washing machine 1 in an embodiment of the present disclosure. An up-down direction in FIG. 1 is called as an up-down direction Z of the washing machine 1; and a left-right direction in FIG. 1 is called as a transverse direction Y of the washing machine 1. The up-down direction Z is consistent with a vertical direction, and the transverse direction Y is consistent with a horizontal direction. In the up-down direction Z, an upper side is called as an upper side Z1, and a lower side is called as a lower side Z2.

Although the washing machine 1 also includes a washing and drying machine with a drying function, the washing machine 1 is described by taking a washing machine which only executes the washing operation as an example below without explaining the clothes drying function. The washing machine 1 includes a housing 2, as well as an outer drum 3, a washing drum 4, a motor 5, a water supply path 6, a water supply valve 7, a detergent accommodating part 8, a drain path 9, a first drain valve 10, a circulating path 11, a pump 12 and a water tank 13 which are arranged in the housing 2.

The housing 2 is, for example, made of metal, and is formed in a shape of a box. An outlet-inlet 2B for communicating the interior and the exterior of the housing 2 is formed in an upper surface 2A of the housing 2. The upper surface 2A is provided with a door 14 for opening and closing the outlet-inlet 2B, and a display and operation part 15 which includes a switch, a liquid crystal panel and the like. A user operates, for example, the switch of the display and operation part 15, to switch on or cut off a power supply of the washing machine 1, or freely set a washing operation mode or issue an instruction of starting or stopping the washing operation to the washing machine 1. The information relating to the washing operation is displayed visually, for example, on the liquid crystal panel of the display operating part 15.

The outer drum 3 is, for example, made of resin, is formed in a cylindrical shape with a bottom, and is elastically supported by the housing 2 via elastic supporting members (not shown) such as so-called hoisting rods. Water may be stored in the outer drum 3. An imaginary straight line passing through a center of a circle of the outer drum 3 is an axis J of the outer drum 3. The axis J extends longitudinally along the vertical direction or a direction which is slightly inclined relative to the vertical direction. The cylindrical outer drum 3 with a bottom includes: a circumferential wall 3A with a substantially cylindrical shape arranged along the axis J, a bottom wall 3B with a circular plate shape for blocking a hollow part of the circumferential wall 3A from the lower side Z2, and an annular wall 3C with a ring shape for hemming an upper edge of the circumferential wall 3A and extending towards the axis J. The outer drum 3 is formed with a circular outlet-inlet 3D encircled by the annular wall 3C and opposed to the outlet-inlet 2B of the housing 2 from the lower side Z2, and a through hole 3E which penetrates through the center of circle of the bottom wall 3B along the up-down direction Z.

The washing drum 4 is a metal drum formed with a bottomed cylindrical shape smaller than the outer drum 3, and may accommodate washings Q. The washing drum 4 is coaxially accommodated into the outer drum 3. Therefore, the axis of the washing drum 4 is the above axis J. The cylindrical washing drum 4 with a bottom includes: a circumferential wall 4A with a substantially cylindrical shape arranged along the axis J, a bottom wall 4B with a circular plate shape for blocking a hollow part of the circumferential wall 4A from the lower side Z2, and an annular wall 4C with a ring shape for hemming an upper edge of the circumferential wall 4A and extending towards the axis J. The washing drum 4 is formed with a circular outlet-inlet 4D encircled by the annular wall 4C and opposed to the outlet-inlet 3D of the outer drum 3 from the lower side Z2, and a number of through holes 4E which penetrate through the circumferential wall 4A and the bottom wall 4B.

When the above door 14 is opened, since the outlet-inlet 2B, the outlet-inlet 3D and the outlet-inlet 4D are exposed to the upper side Z1 from the upper surface 2A of the housing 2 in a state where the outlet-inlet 2B, the outlet-inlet 3D and the outlet-inlet 4D are arranged along the up-down direction Z, the washings Q can be thrown in or taken out of the washing drum 4 via the outlet-inlet 2B, the outlet-inlet 3D and the outlet-inlet 4D. The water in the outer drum 3 not only passes through the through holes 4E to flow between the outer drum 3 and the washing drum 4, but also is accumulated in the washing drum 4. Therefore, a water level in the outer drum 3 is consistent with a water level in the washing drum 4. A rotating shaft 17 which protrudes to the lower side Z2 along the axis J is arranged at the center of circle of the bottom wall 4B. The rotating shaft 17 is inserted into the through hole 3E of the bottom wall 3B of the outer drum 3 from the upper side Z1.

The motor 5, for example, consists of a variable frequency motor. The motor 5 is arranged on the lower side Z2 of the outer drum 3 in the housing 2, and is fixed to the bottom wall 3B of the outer drum 3 via a fixing member (not shown) and the like. The motor 5 has an output shaft 18 which rotates about the axis J. The output shaft 18 is connected to the rotating shaft 17 of the washing drum 4. When the motor 5 is driven, a driving force generated by the motor 5 is transferred from the rotating shaft 17 to the output shaft 18, and the washing drum 4 rotates about the axis J under the driving force. It should be noted that a transmission mechanism (not shown) composed of a clutch can be disposed between the rotating shaft 17 and the output shaft 18. In addition, a pulsator (not shown), which rotates to agitate the accommodated washings Q, is arranged in the washing drum 4, and the driving force of the motor 5 may also be selectively transmitted from the transmission mechanism to one or both of the washing drum 4 and the pulsator. In addition, in the present implementation, for illustration purposes, the number of revolutions of the motor 5 is equal to the number of revolutions of the washing drum 4 and the pulsator.

The water supply path 6 is a flow path which includes one end part 6A connected to a tap (not shown) and another end part 6C formed with a discharge opening 6B. The another end part 6C of the water supply path 6 penetrates through the annular wall 3C of the outer drum 3 from the upper side Z1, and the discharge opening 6B is arranged in a manner of facing a clearance 19 in the transverse direction Y between the circumferential wall 3A of the outer drum 3 and the circumferential wall 4A of the washing drum 4 from the upper side Z1.

The water supply valve 7 is arranged in the middle of the water supply path 6. The water supply path 6 is opened when the water supply valve 7 is opened. Thus, the water from the tap, as shown by a thick solid arrow, passes through the water supply path 6, flows down to the clearance 19 from the discharge opening 6B and is accumulated in the outer drum 3. At this moment, the discharge opening 6B discharges the water, which has flowed into the water supply path 6, towards the clearance 19 between the outer drum 3 and the washing drum 4, i.e., a position staggered with the washings Q in the washing drum 4. The water accumulated in the outer drum 3 is also accumulated in the washing drum 4 through the through holes 4E of the washing drum 4. In this way, when the water supply valve 7 is opened, the water is supplied for the washing drum 4 from the water supply path 6. On the other hand, since the water supply path 6 is closed when the water supply valve 7 is closed, water supply can be stopped.

The detergent accommodating part 8 is formed in a shape of a box for accommodating detergents, and is connected to the middle of the water supply path 6. An inner space of the detergent accommodating part 8 constitutes a middle part of the water supply path 6. When the water supply valve 7 is opened to start water supply, the water from the tap passes through the detergent accommodating part 8 and is mixed with the detergents, flows into the water supply path 6 and then is supplied to the outer drum 3 and the washing drum 4 through the discharge opening 6B. Thus, the detergent water containing the detergents can be accumulated in the outer drum 3 and the washing drum 4.

The drain path 9 is a flow path which includes one end part 9A connected to a position on the bottom wall 3B of the outer drum avoiding the through hole 3E from the lower side Z2 and another end part 9B pulled out to an outer part of the housing 2 in a position lower than the end part 9A.

The first drain valve 10 is arranged in the middle of the drain path 9. The drain path 9 is opened when the first drain valve 10 is opened. Thus, the detergent water accumulated in the outer drum 3 and the washing drum 4 is drained out of the washing machine through the drain path 9. In this way, since the drain path 9 is closed when the first drain valve 10 is closed under a state where the water is drained, water drainage can be stopped.

The circulating path 11 is a flow path which includes one end part 11A connected to a part of the drain path 9 between one end part 9A and the first drain valve 10, and another end part 11C formed with a discharge opening 11B. After the circulating path 11 extends from one end part 11A to the transverse direction Y, the circulating path 11 is bent, extends to the upper side Z1 through the clearance between the housing 2 and the outer drum 3, is bent towards the axis J, and reaches another end part 11C. Another end part 11C is bent directly above the outlet-inlet 3D of the outer drum 3 to the lower side Z2; and the discharge opening 11B is opened at the lower end of another end part 11C, and faces the inner part of the washing drum 4 from the upper side Z1 from the outlet-inlet 4D of the washing drum 4. The pump 12 is, for example, a centrifugal pump in which rotating impeller (not shown) are arranged, and is arranged in the middle of the circulating path 11.

The water tank 13 is a hollow body having, for example, a capacity of about 30 L, and is arranged in a space closer to the lower side Z2 than the outer drum 3 in the housing 2. The water tank 13 is mounted between a connecting part of the drain path 9 connected to one end part 11A of the circulating path 11 and one end part 9A. An inner space of the water tank 13 constitutes a middle part of the drain path 9. An upper flow path 9C of the drain path 9 from one end part 9A to the water tank 13 is a flow path that communicates the outer drum 3 to the water tank 13, extends from the bottom wall 3B of the outer drum 3 to the lower side Z2 and is connected to a top wall of the water tank 13 from the upper side Z1. Thus, the water tank 13 is connected to the outer drum 3 via the upper flow path 9C. The upper flow path 9C is provided with a second drain valve 22 for opening and closing the upper flow path 9C.

For the lower flow path 9D of the drain path 9 from the water tank 13 to another end part 9B, the upper end part of the lower flow path 9D is connected to the bottom wall of the water tank 13 from the lower side Z2. The lower flow path 9D is provided with the above first drain valve 10. One end part 11A of the circulating path 11 is connected to a part of the lower flow path 9D between the first drain valve 10 and the water tank 13. It should be noted that the water tank 13 can be fixed to either the outer drum 3 or the lower part of the housing 2. Under a condition where the water tank 13 is fixed to the lower part of the housing 2, at least the upper flow path 9C of the drain path 9 has flexibility, so that vibration generated by the outer drum 3 in the washing operation is not transferred to the water tank 13.

When both of the first drain valve 10 and the second drain valve 22 are opened, the detergent water which flows from the outer drum 3 to the drain path 9 passes through the water tank 13 and then reaches another end part 9B, and is drained from the washing machine. On the other hand, when the first drain valve 10 is closed under a state where the second drain valve 22 is opened, the detergent water which flows from the outer drum 3 to the upper flow path 9C of the drain path 9 is not drained from the washing machine, but is received by the water tank 13 and accumulated into the water tank 13. As described above, since the water tank 13 is located in a position closer to the lower side Z2 than the outer drum 3 and the upper flow path 9C extends from the bottom wall 3B of the outer drum 3 to the lower side Z2 and is connected to a top wall of the water tank 13 from the upper side Z1, the detergent water in the outer drum 3 successfully flows into the water tank 13 under the weight of the detergent water.

An exhaust hole 13A communicated into the water tank 13 from the upper side Z1 is formed in the top wall of the water tank 13. In relation to the exhaust hole 13A, the washing machine 1 includes an exhaust pipe 23. The exhaust pipe 23 has one end part 23A connected to the exhaust hole 13A from the upper side Z1 and another end part 23B connected to an upper part of the outer drum 3 from the transverse direction Y, and extends from one end part 23A to another end part 23B towards the upper side Z1. The upper part 3F means a part of the circumferential wall 3A of the outer drum 3, which is closer to the upper side Z1 than the assumed upper limit water level in the outer drum 3.

When the detergent water in the outer drum 3 flows into the water tank 13, since air in the water tank 13 escapes from the water tank 13 via the exhaust hole 13A, the detergent water can successfully flow into the water tank 13. Moreover, another end part 23B of the exhaust pipe 23 is connected to the upper part 3F of the outer drum 3, so that bubbles in the water tank 13 can be guided into the outer drum 3 even if the bubbles enter the exhaust pipe 23. Therefore, a situation where the bubbles block the exhaust pipe 23 can be inhibited. In addition, another end part 23B connected to the upper part 3F of the outer drum 3 is arranged in a position higher than the upper limit water level in the outer drum 3. Therefore, the water in the outer drum 3 can be prevented from overflowing into the exhaust pipe 23.

The pump 12 is driven to take the detergent water in the water tank 13 into one end part 11A of the circulating path 11 and to lift the detergent water in the circulating path 11. Thus, the detergent water is taken into the circulating path 11 from the water tank 13, and is discharged through the discharge opening 11B of another end part 11C. The detergent water discharged through the discharge opening 11B, as shown by a thick dotted arrow, flows down to the outlet-inlet 4D of the washing drum 4, and is injected into the washing drum 4 from the upper side Z1. When the pump 12 is continuously driven, the detergent water in the water tank 13 is circulated between the washing drum 4 and the circulating path 11. The pump 12 is arranged in a lowest part of a space closer to the lower side Z2 than the outer drum 3 in the housing 2 (in a position lower than the water tank 13). Therefore, the detergent water in the water tank 13 is taken into the circulating path 11 without residue.

The washing machine 1 includes a control part 30 as an execution unit. The control part 30 is, for example, a microcomputer that includes a CPU and a memory such as ROM and RAM, and is arranged in the housing 2. By referring to the block diagram illustrating an electrical structure of the washing machine las shown in FIG. 2, the washing machine 1 also includes a water level sensor 31, a rotation sensor 32 and a timer 33 for timing. The water level sensor 31, the rotating sensor 32 and the timer 33, as well as the motor 5, the pump 12, the display and operation part 15, the water supply valve 7, the first drain valve 10 and the second drain valve 22 described above, are electrically connected to the control part 30 respectively.

The water level sensor 31 is a sensor which detects water levels in the outer drum 3 and the washing drum 4, and a detection result of the water level sensor 31 is inputted into the control part 30 in real time. The rotation sensor 32 is an apparatus which reads the number of revolutions of the motor 5 (strictly speaking, reads the number of revolutions of the output shaft 18 of the motor 5). For example, the rotation sensor 32 is composed of a Hall IC (not shown) that outputs a pulse wave each time the output shaft 18 rotates by a specified rotation angle. The number of revolutions read by the rotation sensor 32 is inputted into the control part 30 in real time. The control part 30 controls voltage applied to the motor 5 based on the inputted number of revolutions, and specifically controls a duty ratio of voltage applied to the motor 5 so that the motor 5 is driven to rotate at desired revolutions. The control part 30 also controls the driving of the pump 12.

As described above, when the user operates the display and operation part 15 to select operation conditions such as washing operation, the control part 30 receives the selection. The control part 30 displays necessary information to the user on the display and operation part 15 in a visual manner. The control part 30 controls the opening and closing of the water supply valve 7, the first drain valve 10 and the second drain valve 22. Therefore, the control part 30 may open the water supply valve 7 to supply water to the outer drum 3 and the washing drum 4 in a state of at least closing the first drain valve 10, may open the second drain valve 22 to store water in the water tank 13 in a state of closing the first drain valve 10, and may execute drainage of the outer drum 3, the washing drum 4 and the water tank 13 by opening the first drain valve 10 and the second drain valve 22.

Next, the washing operation executed by the control part 30 in the washing machine 1 is illustrated. The washing operation includes: a washing process consisting of an initial dewatering washing process and a formal washing process after the dewatering washing process, a rinsing process after the washing process, and a dewatering process. The dewatering washing process may be regarded as an independent process in the washing operation, or may be regarded as part of the washing process as described in the present embodiment. The dewatering process includes: a final dewatering process executed at the end of the washing operation, and an intermediate dewatering process executed after the washing process and the rinsing process.

Before the washing operation starts, the control part 30 detects the amount of the washings Q in the washing drum 4 as a load. The unit of the load is, for example, kilogram (kg). As an example of the detection of the load, the control part 30 may acquire the load according to the weight of the washings Q detected by a weight sensor (not shown) included in the washing machine 1. In addition, the load is detected through fluctuation of the revolutions of the motor 5 during the steady low-speed rotation of the washing drum 4. In addition, when the above pulsator is adopted, the control part 30 stops driving the motor 5 and enables the motor 5 to perform inertial rotation immediately after the pulsator with the washings Q rotates for a specified time, and measures the amount of inertial revolutions of the motor 5 at this moment. The larger the load is, the smaller the amount of inertial revolutions of the motor 5 connected with the pulsator which bears heavy washings Q is. The smaller the load is, the larger the amount of inertial revolutions of the motor 5 connected with the pulsator which bears light washings Q is. The control part 30 detects the load according to the number of the inertial revolutions.

By referring to the flow chart of FIG. 3, a circulating process and an impregnation process are described. In a dewatering washing process, the first drain valve 10 is always in a closed state, and the second drain valve 22 is always in an opened state in principle. As the dewatering washing process is started, the control part 30 only opens the water supply valve 7 for a specified time to supply water (step S1). Thus, the detergent water which flows from the discharge opening 6B of the water supply path 6 arrives at the water tank 13 through the outer drum 3 and the upper flow path 9C of the drain path 9, and is accumulated into the water tank 13.

Next, the control part 30 implements first circulating treatment (step S2). In the circulating treatment, the control part 30 drives the pump 12 so that the detergent water is circulated between the washing drum 4 and the circulating path 11, and then the detergent water is sprinkled from the discharge opening 11B of the circulating path 11 to the washings Q in the washing drum 4. Treatment time of the circulating treatment (i.e., the time of driving the pump 12) is, for example, about 15 seconds. In addition, the amount of the detergent water sprinkled on the washings Q in the first circulating treatment is about 3 times of the weight of the washings Q. For example, for the washings Q of 8 kg, the amount of the detergent water is about 24 L, which is very large. In addition, for the detergent water that passes through the pump 12 in the circulating path 11, since the detergents are broken and refined by the impeller of the pump 12 and dissolved in the water, high-concentration detergent water can be generated.

After the circulating treatment, the control part 30 implements first impregnation treatment (step S3). In the impregnation treatment, the control part 30 stops driving the pump 12 and enables the detergent water to impregnate the washings Q in the washing drum 4. Specifically, the detergent water sprinkled on the washings Q from the upper side Z1 in the circulating treatment is permeated into the washings Q under the weight of the detergent water. In addition, in the impregnation treatment, since the second drain valve 22 continues being in an opened state, the detergent water not permeated into the washings Q flows to the outer drum 3 via the through holes 4E of the washing drum 4 and returns to the water tank 13 from the upper flow path 9C of the drain path 9.

After the impregnation treatment, the control part 30 implements first dewatering treatment (step S4). In the dewatering treatment, the control part 30 drives the motor 5 so that the washing drum 4 rotates. Thus, since the centrifugal force caused by the rotation of the washing drum 4 acts on the washings Q in the washing drum 4, the washings Q are dewatered.

Next, the control part 30 implements second circulating treatment (step S5), then implements second impregnation treatment (step S6), and next implements second dewatering treatment (step S7). In addition, in the dewatering treatment before the circulating treatment, the detergent water which is squeezed from the washings Q through dewatering returns to the water tank 13 through the outer drum 3 and the upper flow path 9C of the drain path 9. In addition, as described above, in the impregnation treatment before the dewatering treatment, the detergent water also returns to the water tank 13 from the washing drum 4. Therefore, when the circulating treatment after the dewatering process is started, a large amount of the detergent water is accumulated in the water tank 13. Therefore, in the circulating treatment, the circulation of the detergent water can be rapidly started in a manner that the pump 12 does not idle. In addition, in the first circulating treatment, since the washings Q before washing are in a state of being dry and capable of absorbing a large amount of detergent water, the treatment time is set to be long. However, since the washings Q are in a state of absorbing a certain amount of detergent water after the second circulating treatment starts, the treatment time is set to be shorter than the treatment time of the first circulating treatment. Based on the same reason, the treatment time is set to be long in the first impregnation treatment, but from the second impregnation treatment, the treatment time is set to be shorter than the treatment time of the first impregnation treatment.

In the dewatering washing process, the control part 30 repeatedly and successively conducts circular treatment (step S5), impregnation treatment (step S6) and dewatering treatment (step S7), until the dewatering treatment is implemented for a total of specified times (“No” in step S8). In an embodiment, the above specified times are 25 times. In this case, the circulating treatment and the impregnation treatment are repeated for 25 times respectively. In addition, instead of the time elapsed from the water supply in the step S1, the implementation times of the dewatering treatment are used as the judgment criterion in step S8 in consideration of the situation where the dewatering treatment is interrupted when the number of revolutions of the washing drum 4 are not raised to target maximum revolutions due to bias of the washings Q and the like.

The repeat implementations of the circulating treatment enable the detergent water in the water tank 13 to be sufficiently sprinkled on the washings Q in the washing drum 4; and in the impregnation treatment after each circulating treatment, the washings Q are treated by a sufficient amount of detergent water into a state equivalent to soaking. Thus, dirt floats out of the washings Q sufficiently. Moreover, in the dewatering treatment after each impregnation treatment, the dirt is squeezed together with the detergent water from the washings Q under the centrifugal force caused by the rotation of the washing drum 4. In the impregnation treatment before the dewatering treatment, the detergent water in the outer drum 3 and the washing drum 4 returns to the water tank 13. Thus, when the dewatering treatment is started, a water level W in the outer drum 3 is in a state of being lower than the bottom wall 4B of the washing drum 4 (see FIG. 1). Therefore, in the dewatering treatment, the washing drum 4 may not take back the detergent water in the outer drum 3; therefore, the washing drum 4 can successfully rotate to the target maximum revolutions without being hindered by the detergent water and bubbles generated by the detergent water. In addition, since the washing drum 4 in the dewatering treatment loses the detergent water and becomes light, the vibration caused by the rotation of the washing drum 4 is reduced. Therefore, the washings Q can be efficiently dewatered and the dirt can be removed from the washings Q through high-speed rotation of the washing drum 4. As a result of the above, the washing effect of the dewatering washing process conducted by the rotation of the washing drum 4 and the detergent water can be improved. In addition, in the circulating treatment next to the dewatering treatment, a large amount of detergent water that returns to the water tank 13 just now can be used.

In addition, since the revolutions of the washing drum 4 are easy to rise in the dewatering treatment, power consumption of the motor 5 can be reduced. Moreover, the detergent water in the water tank 13 is repeatedly used through repeated circulating treatment.

Thus, a sufficient amount of detergent water can be ensured even if no new detergent water is generated in each dewatering treatment. Therefore, the detergents and the water can also be saved. It should be noted that although the water tank 13 as a member separated from the outer drum 3 is arranged for recycling the detergent water, a concave can be, for example, arranged on the bottom wall 3B of the outer drum 3 and at the later stage of the impregnation treatment, the detergent water in the washing drum 4 returns to the concave. Compared with a situation where such a concave is arranged, in the situation where the water tank 13 is separately arranged, a structure for connecting the rotating shaft 17 of the washing drum 4 to an output shaft 18 of the motor can be easily formed on the periphery of the bottom wall 3B.

Moreover, when the dewatering treatment has been implemented for specified times (“Yes” in step S8), the dewatering washing process is ended and the control part 30 implements a next process, i.e., the formal washing process. As the formal washing process is started, the control part 30 opens the water supply valve 7 and closes the second drain valve 22 under a state where the first drain valve 10 is continuously closed, thereby continuing to supply water for the washing drum 4. At this moment, the control part 30 drives the pump 12, so that the detergent water in the water tank 13 is transferred to the washing drum 4 via the circulating path 11. Thus, the detergent water in the washing drum 4 is accumulated to a water level higher than a water level of the detergent water accumulated through water supply in step S1. In this way, the detergent water in the water tank 13 is also used for water supply, thereby reducing the amount of water supplied through the water supply path 6.

In the formal washing process, the control part 30 drives the motor 5 in a state where the detergent water is accumulated in the washing drum 4, so that the washing drum 4 rotates or the above pulsator rotates. Thus, a water flow of the detergent water is produced in the washing drum 4 and is used for agitating the washings Q. The water flow removes the dirt from the washings Q through mechanical force (e.g., friction, vibration) applied to the washings Q, or chemically decomposes the dirt through the detergent water, thereby formally washing the washings Q.

Especially, since the washings Q are in a state where the dirt is easy to float out through the dewatering washing process before the formal washing process, the formal washing process can achieve a high washing effect. It should be noted that at the end of washing operation (i.e., at the end of the dewatering process), the control part 30 opens both of the first drain valve 10 and the second drain valve 22, thereby executing drainage of all components of the outer drum 3, the washing drum 4 and the water tank 13. Therefore, the water tank 13 is empty in principle at the end of each washing operation.

The control part 30 can also execute, in at least one circulating treatment, first treatment in which the motor 5 is driven while the washing drum 4 rotates at low rotating speed which is less than specified rotating speed. The revolutions of the motor 5 during low-speed rotation of the washing drum 4 are, for example, 50 rpm. In addition, the revolutions of the motor 5 during rotation of the washing drum 4 are, for example, 200 rpm to 800 rpm in the dewatering treatment of the dewatering washing process; and the revolutions of the motor 5 during high-speed rotation of the washing drum 4 are, for example, 600 rpm to 800 rpm in the dewatering process. Through low-speed rotation of the washing drum 4 in the circulating treatment, a situation where the washings Q in the washing drum 4 are biased and the detergent water in the washing drum 4 is splashed outwards from the outlet-inlet 4D can be inhibited. In addition, the control part 30 can also execute, in at least one circulating treatment, second treatment that the driving of the motor 5 is controlled while the washing drum 4 repeatedly rotates intermittently. Intermittent rotation of the washing drum 4 means that the washing drum 4 is repeatedly stopped and rotated through repeatedly powering on and powering off the motor 5.

Through the first treatment and the second treatment, the detergent water that returns through the circulating path 11 to the washing drum 4 can be evenly sprinkled on the washings Q in the washing drum 4 throughout the entire region in the rotating direction of the washing drum 4. Therefore, the washing effect can be further improved in the dewatering washing process.

The control part 30 may also execute, in the dewatering washing process, third treatment in which the washing drum 4 is stopped in the circulating treatment and the motor 5 is driven to rotate the washing drum 4 by only a specified angle before next circulating treatment is started. Thus, under a state where the washing drum 4 is stopped in the circulating treatment, most of the washing water may be sprinkled in one position in the rotating direction of the washing drum 4 of the washings Q. Moreover, the control part 30 enables the washing drum 4 to slightly rotate from the stopping position in the previous circulating treatment before the next circulating treatment is started, thereby sprinkling, in the next circulating treatment, most of the washing water in a position of the washings Q different from the position in which the washing water is sprinkled in the previous circulating treatment. In addition, the stopping position in the previous circulating treatment is temporarily stored by the control part 30. In this way, the circulating treatment is repeated while the position of the washings Q in which the detergent water is impregnated is changed slightly; and finally, a sufficient amount of detergent water can be evenly sprinkled on the washings Q in the washing drum 4 throughout the entire region in the rotating direction of the washing drum 4. Therefore, the washing effect can be further improved by the detergent water.

In the dewatering washing process, only any treatment of the first treatment to the third treatment is implemented, or a combination of multiple treatments of the first treatment to the third treatment is implemented. For example, in the first circulating treatment to fifth circulating treatment at the beginning of the dewatering washing process, only the first treatment is implemented; and from sixth circulating treatment, only the third treatment is implemented. In this case, through the first circulating treatment to the fifth circulating treatment, at an initial stage of the dewatering washing process, the detergent water can be evenly sprinkled on washings Q; and from the sixth circulating treatment, a large amount of detergent water is locally sprinkled on washings Q. Thus, the washing effect of part of the washings Q in which the detergent water is impregnated can be improved.

In addition, a combination of the first treatment to the third treatment can be set arbitrarily according to the load of the washings Q and the washing operation mode. For example, under a condition where the load is small for fewer washings Q and in a mode of cotton which can easily absorb water, since the detergent water is easy to infiltrate into the lower part of the washings Q even if only a small amount of detergent water is evenly sprinkled on the washings Q, frequencies of the first treatment and second treatment are increased and the frequency of the third treatment is decreased. On the other hand, under a condition where the load is large for too many washings Q and in a mode of heavy blanket, since the detergent water is difficult to infiltrate into the lower part of the washings Q if a large amount of detergent water is not locally sprinkled on the washings Q, the frequency of the third treatment is increased and the frequencies of the first treatment and the second treatment are decreased.

The control part 30 can open the water supply valve 7 in step S1 of the circulating impregnation process to supply part of water supply amount in the overall washing process to the washing drum 4, so as to generate the detergent water. Thus, water can be saved in the overall washing operation, and high-concentration detergent water can be generated. In addition, the water supply amount in the overall washing process is, for example, 60 L. In this case, the water supply amount in the circulating impregnation process is set as ⅓ to ½ of 60 L, e.g., 20 L.

In this way, in the circulating treatment process, the high-concentration detergent water is generated through small amounts of detergents and water, and the circulating treatment and the impregnation treatment in which the detergent water is evenly impregnated on the washings Q through the pump 12 are repeatedly conducted, thereby obtaining a washing effect equivalent to the washing effect of a condition of immersion washing conducted using a large amount of high-concentration detergent water. In addition, high concentration herein means, for example, a range of 2-3 times of the concentration.

In addition, the control part 30 may also close the second drain valve 22 only for a certain time in at least one impregnation treatment, so as to accumulate the detergent water in the washing drum 4. As a result, the washings Q can be efficiently treated into a state equivalent to soaking through a sufficient amount of detergent water accumulated in the washing drum 4. Therefore, the washing effect can be further improved in the dewatering washing process. It should be noted that all the detergent water in the water tank 13 may be accumulated in the washing drum 4. Thus, the state equivalent to soaking can be further achieved efficiently. Moreover, in the impregnation treatment under a condition where the second drain valve 22 is closed, the second drain valve 22 is opened after the above time elapsed, and the detergent water in the outer drum 3 and the washing drum 4 returns to the water tank 13.

In addition, as described above, when water supply in step S1 is conducted, the discharge opening 6B of the water supply path 6 discharges the water that passes through the detergent accommodating part 8 and carries the detergents towards a position of the washings Q staggered with the washings Q in the washing drum 4. In other words, when water supply of the circulating impregnation process is conducted, the water that carries the detergents of the detergent accommodating part 8 is supplied in a manner where the water is not directly dropped on the washings Q, thereby inhibiting a situation where the washings Q cannot be evenly washed because detergents with super-high concentration before dissolved in the water are only attached to part of the surface of the washings Q.

The control part 30 may also change the treatment time of the circulating treatment, the impregnation treatment and the dewatering treatment according to the load of the washings Q in the washing drum 4. Specifically, under a situation where the load is large for too many washings Q, since a large amount of detergent water needs to be sprinkled on the washings Q to impregnate the washings Q, the control part 30 often sets the treatment time of the circulating treatment and the impregnation treatment to be longer. In addition, since it takes long time to dewater the washings Q impregnated with a large amount of detergent water, the control part 30 also often sets the treatment time of the dewatering treatment to be longer. On the other hand, under a situation that the load is small for fewer washings Q, since a sufficient washing effect can be obtained as long as a small amount of detergent water is sprinkled on the washings Q to impregnate the washings Q, the control part 30 often sets the treatment time of the circulating treatment and the impregnation treatment to be shorter. In addition, since it takes short time to dewater the washings Q impregnated with a small amount of detergent water, the control part 30 also often sets the treatment time of the dewatering treatment to be shorter. Thus, a most appropriate circulating impregnation process can be executed according to each load. Therefore, the washing effect can be further improved by the detergent water of the dewatering washing process.

The present disclosure is not limited to above described embodiments, and can be changed in various modes within a scope recorded in claims.

For example, in the washing operation, the circulating impregnation process which is equivalent to omitting the dewatering treatment in the dewatering washing process is implemented before the dewatering washing process. In the circulating impregnation process, after a specified time elapsed from the beginning of water supply, the circulating treatment and the impregnation treatment are repeatedly conducted. In this case, the washings Q are treated into the state equivalent to soaking through the high-concentration detergent water. Thus, since the dirt is floated out of the washings Q in advance, the washings Q can be efficiently washed in the later dewatering washing process. It should be noted that, since the detergent water is generated in a stage prior to the dewatering washing process under a condition where the circulating impregnation process is implemented, water supply in step S1 in the dewatering washing process can be omitted, or the water from the discharge opening 6B of the water supply path 6 is directly sprinkled on the washings Q when the water supply is conducted.

In addition, the formal washing process may be omitted in the washing operation, and the rinsing process may be implemented immediately after the dewatering washing process. In the formal washing process, since a great mechanical force acts on the washings Q, the washings

Q may be damaged or the washings Q may be wound together and are difficult to take out after washing operation. Through the dewatering washing process, the mechanical force that causes damage and winding is difficult to act on the washings Q. Therefore, when the washings Q are washed mainly through the dewatering washing process, damage and winding to the washings Q can be reduced. In this case, in the dewatering washing process, the circulating treatment and the impregnation treatment are repeatedly conducted, so that the washings Q can be treated into a state equivalent to soaking through a sufficient amount of detergent water. Moreover, in the dewatering treatment, since the detergent water is in a state of returning to the water tank 13 in the previous impregnation treatment, the washing drum 4 can rotate at high speed without being hindered by the detergent water, so as to remove the dirt from the washings Q. Therefore, even if the formal washing process is omitted, the washing effect can be achieved sufficiently.

In addition, although one end part 11A of the circulating path 11 is connected to the drain path 9 (see FIG. 1) in above embodiments, the end part 11A may also be directly connected to the lower end part of the water tank 13.

FIG. 4 is a schematic diagram illustrating a washing machine 1 in a first variation example. FIG. 5 is a schematic diagram illustrating a washing machine 1 in a second variation example. FIG. 6 is a schematic diagram illustrating a washing machine 1 in a third variation example. In FIG. 4 to FIG. 6, same reference signs are given to the parts which are the same as the parts described in FIG. 1, and illustration of the parts is omitted.

As a structure configured to supply the water that carries the detergents in a manner where the water is not directly dropped on the washings Q when water supply in step S1 in the dewatering washing process is conducted, as described above, the discharge opening 6B of the water supply path 6, as shown by a thick solid arrow in FIG. 1, discharges the water towards the clearance 19 between the outer drum 3 and the washing drum 4, i.e., a position staggered with the washings Q in the washing drum 4. As a variation example of the structure, a first variation example and a second variation example can be illustrated.

In the first variation example shown in FIG. 4, the water supply path 6 passes between the circumferential wall 3A of the outer drum 3 and the housing 2 from the detergent accommodating part 8 and extends to the lower side Z2, and another end part 6C of the water supply path 6 is connected to the lower end part of the circumferential wall 3A. In this case, the water supply path 6 is a flow path that passes through the outside of the outer drum 3, and the discharge opening 6B of another end part 6C faces the lower end part of the clearance 19 between the outer drum 3 and the washing drum 4 from the transverse direction Y. On the other hand, the washing machine 1 of the first variation example includes a branch path 25 branched from the water supply path 6 on the detergent accommodating part 8. The branch path 25 is a flow path that extends from the detergent accommodating part 8 to the lower side Z2, and a water supply opening 25A that faces the outlet-inlet 4D of the washing drum 4 from the upper side Z1 is formed in the lower end of the branch path 25. A water supply valve 26 is arranged in a middle of the branch path 25. When the first variation example is described below, for illustration purposes, the water supply valve 7 is called as a first water supply valve 7 and the water supply valve 26 is called as a second water supply valve 26. The opening and closing of the water supply valve 26 are controlled by the control part 30.

In the dewatering washing process of the first variation example, when water supply in step S1 is conducted, the control part 30 opens the first water supply valve 7 under a state of closing the second water supply valve 26. Thus, after the water from the tap passes through the detergent accommodating part 8, carries the detergents and flows down to the water supply path 6, as shown by a thick solid arrow, the water is supplied through the discharge opening 6B into the outer drum 3 in a space 27 closer to the lower side Z2 than the bottom wall 4B of the washing drum 4. At this moment, the discharge opening 6B discharges the water, which passes through a guiding flow path 29, towards the space 27, i.e., a position staggered with the washings

Q in the washing drum 4. Thus, the water mixed with the detergents is supplied in a manner that the water is not directly dropped on the washings Q. On the other hand, under a condition where water supply in the formal washing process after the dewatering washing process is conducted, the control part 30 opens the second water supply valve 26 under a state of closing the first water supply valve 7. Thus, the water from the tap is directly supplied into the washing drum 4 from the water supply opening 25A through the branch path 25. In other words, initial water supply is executed using the water supply path 6, and later water supply is executed using the branch path 25.

In the second variation example shown in FIG. 5, another end part 6C of the water supply path 6 penetrates through the outlet-inlet 3D of the outer drum 3, and the discharge opening 6B of another end part 6C faces the outlet-inlet 4D of the washing drum 4 from the upper side Z1. A guiding part 28 is arranged in the washing drum 4 of the washing machine 1 in the second variation example. The guiding part 28 is in a shape of a water guiding groove that extends along the axis J in the up-down direction Z throughout a range from an upper end part to a lower end part of the circumferential wall 4A of the washing drum 4, and a top cross section of the guiding part 28 is formed in a shape of a circular arc that is bent towards the axis J. The guiding part 28 is fixed to the circumferential wall 4A in a manner of covering one position on the circumference of the circumferential wall 4A from the side of the axis J. Thus, a guiding flow path 29 that extends in the up-down direction Z is formed between the guiding part 28 and the circumferential wall 4A. The upper end part of the guiding part 28 is an accepting part 28A which is formed in a shape of a bowl expanded towards the axis J. The guiding flow path 29 is exposed from the accepting part 28A to the upper side Z1. The discharge opening 6B is opposed to the accepting part 28A from the upper side Z1.

In the dewatering washing process of the second variation example, when water supply in step S1 is conducted, the control part 30 opens the water supply valve 7. Thus, the water from the tap passes through the detergent accommodating part 8, is mixed with the detergents, and passes through the water supply path 6, as shown by a thick solid arrow, and then the water is dropped to the accepting part 28A of the guiding part 28 from the discharge opening 6B. The water accepted by the accepting part 28A flows in the guiding flow path 29, leaks through the through holes 4E of the washing drum 4 to the outside of the washing drum 4, and reaches the outer drum 3 in the space 27 closer to the lower side Z2 than the bottom wall 4B of the washing drum 4. At this moment, the discharge opening 6B discharges the water that passes through the guiding flow path 29 towards the guiding part 28, i.e., a position staggered with the washings Q in the washing drum 4. Thus, the water mixed with the detergents is supplied in a manner that the water is not directly dropped on the washings Q.

In the third variation example shown in FIG. 6, the circulating path 11 includes: a main flow path 11D that extends from one end part 11A to another end part 11C. The circulating path 11 has the discharge opening 11B and a branch flow path 11E branched from the main flow path 11D. Although the branch flow path 11E is connected to the lower end part of the circumferential wall 3A of the outer drum 3 from the transverse direction Y in FIG. 6, the branch flow path 11E may also be connected to the water tank 13 instead of the outer drum 3. A reversing valve 35 is arranged on a connecting part between the main flow path 11D and the branch flow path 11E. The reversing valve 35 is a so-called three-way valve, and is connected to both sides of the main flow path 11D that sandwich the reversing valve 35 and the branch flow path 11E. The opening and closing of the reversing valve 35 are controlled by the control part 30, so that the flow of detergent water in the circulating path 11 is switched to the main flow path 11D or the branch flow path 11E.

Therefore, the flow of detergent water in the circulating path 11 is switched to the main flow path 11D in the circulating treatment, so that the detergent water is circulated between the washing drum 4 and the circulating path 11. In addition, the flow of detergent water in the circulating path 11 is switched to the branch flow path 11E at a time point earlier than the circulating treatment, so that the detergent water in the circulating path 11 does not reach the washing drum 4, but directly enters the outer drum 3 or the water tank 13 through the branch flow path 11E. Thus, since a frequency at which the detergent water flows through the pump 12 can be increased and stirring of the detergent water by the pump 12 can be promoted, the detergents can be efficiently dissolved in the water to generate high-concentration detergent water. Therefore, the washing effect can be further improved through the high-concentration detergent water in the dewatering washing process. 

What is claimed is:
 1. A washing machine, comprising: an outer drum, which is capable of storing water; a washing drum, which is accommodated in the outer drum and is used for accommodating washings, wherein the washing drum has an axis extending longitudinally and a plurality of through holes, the through holes are used for enabling water to flow between the washing drum and the outer drum; a motor, which is used for rotating the washing drum; a water tank, which is connected to the outer drum and is used for receiving detergent water containing detergents from the outer drum; a circulating path, which is used for taking the detergent water from the water tank and injecting the detergent water into the washing drum from an upper side of the washing drum; a pump, which is used for taking the detergent water in the water tank into the circulating path and lifting the detergent water in the circulating path; and an execution unit, which is used for executing a washing operation, wherein the washing operation comprises a dewatering washing process which repeatedly conducts circulating treatment, impregnation treatment and dewatering treatment, the circulating treatment is to drive the pump to enable the detergent water in the water tank to circulate between the washing drum and the circulating path and to sprinkle the detergent water on the washings in the washing drum; the impregnation treatment is to stop driving the pump after the circulating treatment and to enable the detergent water to impregnate the washings in the washing drum and return to the water tank; the dewatering treatment is to drive the motor to rotate the washing drum to dewater the washings after the impregnation treatment.
 2. The washing machine according to claim 1, wherein the execution unit drives the motor in at least one circulating treatment to rotate the washing drum.
 3. The washing machine according to claim 1, wherein the water tank is provided with an exhaust hole; and the washing machine comprises an exhaust pipe, which has one end part connected to the exhaust hole and another end part connected to an upper part of the outer drum.
 4. The washing machine according to claim 1, wherein the washing machine comprises: a water supply path, which is used for supplying water for the washing drum; and a detergent accommodating part, which is connected to the water supply path and is used for accommodating the detergents, wherein the water supply path has a discharge opening, the discharge opening is used for discharging the water that passes through the detergent accommodating part and flows through the water supply path towards a position staggered with the washings in the washing drum.
 5. The washing machine according to claim 1, wherein the circulating path comprises a main flow path and a branch flow path, the main flow path has a discharge opening facing the washing drum from an upper side, the branch flow path branches from the main flow path and is connected to one of the outer drum and the water tank, wherein the washing machine comprises a reversing valve, the reversing valve is used for switching a flow of the detergent water in the circulating path to one of the main flow path and the branch flow path.
 6. The washing machine according to claim 1, wherein the washing machine comprises: a flow path, which is used for connecting the outer drum to the water tank, and a valve, which is used for opening and closing the flow path, wherein the execution unit closes the valve in at least one impregnation treatment to accumulate the detergent water in the washing drum.
 7. The washing machine according to claim 2, wherein the water tank is provided with an exhaust hole; and the washing machine comprises an exhaust pipe, which has one end part connected to the exhaust hole and another end part connected to an upper part of the outer drum.
 8. The washing machine according to claim 2, wherein the washing machine comprises: a water supply path, which is used for supplying water for the washing drum; and a detergent accommodating part, which is connected to the water supply path and is used for accommodating the detergents, wherein the water supply path has a discharge opening, the discharge opening is used for discharging the water that passes through the detergent accommodating part and flows through the water supply path towards a position staggered with the washings in the washing drum.
 9. The washing machine according to claim 3, wherein the washing machine comprises: a water supply path, which is used for supplying water for the washing drum; and a detergent accommodating part, which is connected to the water supply path and is used for accommodating the detergents, wherein the water supply path has a discharge opening, the discharge opening is used for discharging the water that passes through the detergent accommodating part and flows through the water supply path towards a position staggered with the washings in the washing drum.
 10. The washing machine according to claim 2, wherein the circulating path comprises a main flow path and a branch flow path, the main flow path has a discharge opening facing the washing drum from an upper side, the branch flow path branches from the main flow path and is connected to one of the outer drum and the water tank, wherein the washing machine comprises a reversing valve, the reversing valve is used for switching a flow of the detergent water in the circulating path to one of the main flow path and the branch flow path.
 11. The washing machine according to claim 3, wherein the circulating path comprises a main flow path and a branch flow path, the main flow path has a discharge opening facing the washing drum from an upper side, the branch flow path branches from the main flow path and is connected to one of the outer drum and the water tank, wherein the washing machine comprises a reversing valve, the reversing valve is used for switching a flow of the detergent water in the circulating path to one of the main flow path and the branch flow path.
 12. The washing machine according to claim 4, wherein the circulating path comprises a main flow path and a branch flow path, the main flow path has a discharge opening facing the washing drum from an upper side, the branch flow path branches from the main flow path and is connected to one of the outer drum and the water tank, wherein the washing machine comprises a reversing valve, the reversing valve is used for switching a flow of the detergent water in the circulating path to one of the main flow path and the branch flow path.
 13. The washing machine according to claim 2, wherein the washing machine comprises: a flow path, which is used for connecting the outer drum to the water tank, and a valve, which is used for opening and closing the flow path, wherein the execution unit closes the valve in at least one impregnation treatment to accumulate the detergent water in the washing drum.
 14. The washing machine according to claim 3, wherein the washing machine comprises: a flow path, which is used for connecting the outer drum to the water tank, and a valve, which is used for opening and closing the flow path, wherein the execution unit closes the valve in at least one impregnation treatment to accumulate the detergent water in the washing drum.
 15. The washing machine according to claim 4, wherein the washing machine comprises: a flow path, which is used for connecting the outer drum to the water tank, and a valve, which is used for opening and closing the flow path, wherein the execution unit closes the valve in at least one impregnation treatment to accumulate the detergent water in the washing drum.
 16. The washing machine according to claim 5, wherein the washing machine comprises: a flow path, which is used for connecting the outer drum to the water tank, and a valve, which is used for opening and closing the flow path, wherein the execution unit closes the valve in at least one impregnation treatment to accumulate the detergent water in the washing drum. 